| 16S | 16 Svedbergs | |
| 3DI | Conscious | |
| A1AT | alpha-1-antitrypsin | |
| A1C | Glycated Hemoglobin | |
| A2N | Anaerobic-Anoxic/Nitrification | |
| AA | Amino Acid | |
| AABE | Asian Association for Biology Education | |
| AABS | Autoantibodies | |
| AAM | American Academy of Microbiology | |
| AAMB | All About Molecular Biology | |
| AAMCC | American Association for Medical Chronobiology and Chronotherapeutics | |
| AAOB | Aerobic Ammonia Oxidizing Bacteria | |
| AAOB | Anaerobic Ammonium Oxidizing Bacteria | |
| ABATS | Automated Biological Agent Testing System | |
| ABBM | Adipose Biology Basic Mechanisms | |
| ABCD | Access to Biological Collection Data | |
| ABCS | Aeromedical Biological Containment System | |
| ABEB | Aquatic Behavioural Evolutionary Biology | |
| ABI | Advances in Biological Informatics | |
| ABI | Artificial Biological Intelligence | |
| ABL | Advanced Biological Laboratories | |
| ABLE | Academic Biology Learning Environment | |
| ABM | Applied Biological Materials | |
| ABMI | Alberta Biodiversity Monitoring Institute | |
| ABMN | Adipocyte Biology and Molecular Nutrition Core |
